History & Research

In the late 1970’s a program was begun at the Semiarid Prairie Agricultural Research Centre at Swift Current, Saskatchewan, Canada to integrate legume green manuring into dry land cereal production. A wide range of adapted and exotic annual legumes was screened with four promising varieties selected for field tests. Multi-location field experiments were conducted from 1984 to 1992 under direction of Dr. V. O. Biederbeck, a Soil and Environmental Microbiologist, from the Research Centre.

The results revealed that chickling vetch (Lathyrus sativus), AC Greenfix, reached green manure maturity earlier, had the greatest potential for nitrogen fixation, and had a higher drought tolerance. On May 27, 1994, the cultivar AC Greenfix was officially registered under the Canada Seeds Act and became commercially available in May 1996 from Johnson Seeds, Arborg, Manitoba.

Dr. Biederbeck and various associates have continued to compare results on cereal crops grown following green manuring with AC Greenfix. Greenfallowing with AC Greenfix was shown in greenhouse, field plot, and farm field studies, to effect not only increases in the amount and in the efficiency of subsequent wheat production, but also to improve grain quality greatly through higher protein contents and larger kernel size. For example, during the dry growing season of 1996, durum yields averaged 42 bushels/acre on disced chickling vetch, 37 bushel on chemfallow, and 31 bushel after disced field peas. The protein ranged from 16.7 to 17.7% after greenfallow legumes and was 15.8 following chemfallow. At the Glenlea Research Farm, located in the Red River Valley of southern Manitoba, Dr. Martin Entz from the Plant Science Dept., University of Manitoba, has been successful in seeding AC Greenfix immediately after harvesting winter cereals (fall rye, winter wheat) and letting it grow until the plants are naturally killed by frost in the late fall to provide nitrogen and enhance soil fertility.

In an effort to determine the maximum rates of dry matter accumulation and nitrogen fixation, frequent sampling was done in two separate locations in southern Saskatchewan during the 2000 growing season by Dr. Biederbeck. The results determined that under optimum growing conditions, during peak vegetative growth, total growth (above and below ground) of AC Greenfix was measured at 150 lbs/acre of dry matter per day, indicating an accumulation of 5 to 6 lbs. of nitrogen per day.

In 1988, Dr. James R. Sims, Plant and Soil Science Dept., Montana State University, Bozeman, Montana, obtained seed to include with 24 other annual legumes in a state-wide trial to study their potential as green manure and annual hay crops. Their research results reported that AC Greenfix (chickling vetch) consistently produced the most forage and generally produced well in both the wetter and dryer environments. To include grazing by livestock as a legume management possibility, Dr. Sims applied the USDA laboratory foam formation test to these annual legumes as a rough index of potential bloat hazard to ruminants and the results from both years showed that AC Greenfix generated the least foam among the 25 annual legumes, as little as sainfoin, known to be the most bloat-safe perennial forage legume.

The forage quality traits of AC Greenfix have also been evaluated as part of the cool season hay annual forage trials conducted at NDSU Carrington Research Extension Center in Carrington, North Dakota. The results reported for 1995-2000 show that AC Greenfix excelled when compared to 15-25 annual legumes, cereals and cereal/legume mixtures. It ranked first in crude protein with contents ranging from 22% to 26%, and was consistently among the top three forages tested in total digestible nutrients and in relative feed value. Animal studies are in progress under the direction of Dr. Rao at the USDA ARS in El Reno, OK., with preliminary results looking very promising. Effect of AC Greenfix (chickling vetch) on gestating ewes was documented at NDSU, Dickinson, North Dakota.

Copies of the research data from which this material was taken are available from the research centers mentioned above or from Dakota Frontier Seeds, Ltd. upon request.